1. Technical Field
The present invention relates to an electro-optical device suitable for use in personal computers and mobile phones, a method for manufacturing the electro-optical device, and an electronic apparatus including the electro-optical device.
2. Related Art
Electro-optical devices such as liquid crystal devices have been used for displays for electronic apparatuses such as personal computers and mobile phones. The liquid crystal devices include semiconductor integrated circuit (IC) chips mounted on substrates by flip chip bonding.
In recent years, small-size high-performance electronic apparatuses have been demanded. Hence, the distance between wires, including terminals, extending on substrates needs to be small, that is, the pitch between the wires needs to be fine.
JP-A-2000-347206 (hereinafter referred to as Patent Document 1) discloses a liquid crystal display. The liquid crystal display includes a liquid crystal display element substrate including a plurality of input and output terminals arranged along an end portion thereof and also includes a driver IC, disposed on a surface of the liquid crystal display element substrate, including a plurality of input and output bumps. The driver IC is mounted on the liquid crystal display element substrate by flip chip bonding in such a manner that the input and output terminals are bonded to the input and output bumps, respectively, with an anisotropic conductive film disposed therebetween. The output bumps are narrow in the arrangement direction thereof; have a triangular, pentagonal, or trapezoidal shape; and are alternately arranged so as to form a first output bump array and a second output bump array. Portions of the output bumps in the second output bump array extend between the output bumps in the first output bump array. The terminals are geometrically similar to the bumps.
According to Patent Document 1, the driver IC, which is attached to a semiconductor IC chip, has a reduced size and the output bumps adjacent to each other are prevented from being electrically shorted. In the liquid crystal display, thin-film transistors are used as display element switches and the substrate has connection terminals electrically connected to gate or source electrodes of the thin-film transistors. Since the elevation from the substrate to the connection terminals connected to the gate electrodes is different from the elevation from the substrate to the connection terminals connected to the source electrodes, there is a problem in that the reliability of the electrical connection of the output bumps to the connection terminals connected to the gate electrodes is low.
In order to improve the reliability of the electrical connection, wires extending from the gate electrodes may be connected to metal interconnects arranged at the same level of the source electrodes such that the elevation from the substrate to the connection terminals connected to the gate electrodes is substantially equal to the elevation from the substrate to the connection terminals connected to the source electrodes. This can solve the above problem. However, the use of such interconnects causes problems that additional wires are required, the pitch between the connection terminals needs to be reduced, and the resistance of the liquid crystal display is increased although the liquid crystal display needs to have a reduced resistance. The use of the interconnects further causes a problem that the size of the driver IC cannot be reduced because the interconnects occupy a large area in the arrangement direction thereof.